To get the best start in looking after your plants there are two simple steps:
Select the right plants. If you choose plants that are difficult to grow in the conditions found in your garden – then you will have a lot of problems, and your garden will always be likely to struggle.
Prepare your garden well, prior to planting. This includes improving the soil, or growing media, providing drainage and shade where required, completely all structural works, and removing weeds.
PREPARING YOUR GARDEN
Consider The Site
Does it have any particular problems which should be treated?
Hard clay soils need to be loosened up by cultivation, or by adding soil conditioners such as lime or gypsum, or by incorporating organic matter, such as well rotted manures and compost.
Sandy soils can sometimes dry out too easily or be low in nutrients. To overcome these problems add well rotted manures or compost, or wetting agents.
Check soil pH (the degree of acidity or alkalinity). Most plants prefer a slightly acid or neutral soil (pH of about 6 to 7.5). Some plants such as Camellias, Azaleas, Daphne and Citrus prefer a pH that is a little more acid than this (less than 6), while other plants (eg. Lilacs) prefer a pH slightly more alkaline. Simple test kits can be readily obtained from nurseries, garden centres, etc. You can then either choose plants that like the pH of your soil/growing media, or you might alter the pH to suit the plants you wish to grow. pH can be raised by the addition of lime, or lowered by the addition of acidifying materials such as Manures, Sulphate of Ammonia, or Sulphur powder (only for small areas as it is relatively expensive).
Provide wind breaks or channel winds with fences or planting, to both protect tender plants and ensure good ventilation (If the garden is totally enclosed, air movement is restricted, and that can result in an increase in diseases.
If necessary, select plants to grow that will tolerate or even prefer periods of shade.
Building Up The Soil
Before you even start a new garden, make sure the soil is in top condition. Make sure drainage, nutrition, the soil type (e.g. sandy, clayey), and the structure of the soil is suitable for the plants you wish to grow. This may involve laying drainage pipes; applying fertilizers, gypsum (to improve the structure of clay soils) or lime; or digging in manure & compost. Thoroughly get rid of existing weeds.
Use Healthy Plants
Healthy plants are more likely to resist damage from pests and diseases, and more likely to recover if they are attacked. The roots and top growth of the plant should be well developed. There should be no deformed growths (eg: twisted, distorted leaves, swellings on roots). Avoid plants with badly marked leaves. Don't use plants contaminated with insects or other pests. Seeds and bulbs should be fresh, free of abnormal markings or any rots.
Maintain Good Hygiene
Remove any diseased fruit, flowers, leaves, or other plant parts, and burn them (do not compost them or let them lay on the ground!). Wash soil off paths, pavers, concrete areas - soil tracked from one area to another may spread disease. Sit plants in containers on stones or paving, or on top of a couple of bricks (not directly on top of soil). This minimises movement of pest & disease organisms from the soil up into the pot. Keep hoses, particularly the nozzles stored off the ground, ideally on a reel or rack to minimise contact with the ground where they may come in contact with disease organisms.
Maintain The Nutrition & Watering Needs Of The Plant
Do not over water or underwater...both are as bad as each other! Over watering (water
logging) is indicated by yellowing of the lower leaves, sometimes wilting and eventually dropping of the lower leaves. Under watering is indicated by browning of the tips and foliage generally, and at times by severe wilting and leaf drop. Lack of nutrients is indicated by a slow rate of growth, and in severe cases, by discolouration patterns on leaves.
In small gardens you need to keep the deepest roots moist; otherwise you will encourage roots to come to the surface in search of water. Do this by giving the garden a good soaking less often, rather than frequent light irrigations. A drip irrigation system is ideal for this purpose.
Inspect Plants Regularly For Evidence Of Pest & Disease Problems
Look at the growing tips first. The young growth will indicate general vigour (or lack of it). The soft tips are also the area of the plant most commonly attacked. Look for die-back, discolouration of leaves or wood, distortion of growth, rots, eaten or broken tissue. If pest or disease problems are noticed then treat them as soon as possible to prevent further decline in the health of the plant/s, and to minimise the likelihood of the problem spreading.